重新编辑cws_Composition内容

<input type="button" value="重新编辑" onclick="clean()"/>
<script type="text/javascript">
    var i="";
    function clean(){
        var b=document.getElementById("cws_Composition").contentWindow;  //cws_Composition
         b.document.body.innerHTML =" ";
         i=" ";
    }
</script>